•Urban agglomeration is an effective model for sustainable urban development.•Regional economic strength should contain the value of unmarketed natural resources.•Small and medium urban ...agglomerations is a more suitable scale for regional synergy.•The ‘enclave economy’ can be further promoted in cross-regional cooperation.
Urban agglomeration has become the main regional unit to cope with global challenges. However, with the development of economic globalisation and urbanisation, urban agglomeration is facing increasing pressure on nature resources and ecological environment. This study takes the Fujian Delta Urban Agglomeration (FDUA) in China as the research area. Emergy analysis theory is used to evaluate the health status of urban agglomeration and its internal cities. Simultaneously, the regional coordination degree model is applied to evaluate the coordination between urban social-economic and resource-environment systems, as well as the coordination among cities. Results show that (1) the FDUA is a consumption-orientated economic system (emergy-based sustainability index < 1), and the social and economic development is dominated by a non-renewable resource input (58.95%) and in a low environmental load state (1.33 < environmental loading ratio < 1.76). (2) The level of urban economic development is characterised by ‘Xiamen > Quanzhou > Zhangzhou’, an order that is associated positively with the demand for external feedback-type emergy, but negatively with the production efficiency of the ecological economy. (3) The regional social-economic and resource-environment systems of the cities in FDUA are moderately uncoordinated states (0.35 ≤ D ≤ 0.4), but the FDUA is generally weakly coordinated (0.52 ≤ D ≤ 0.56). The co-development model of the urban agglomeration is considerably beneficial to the sustainable development of cities. (4) Cross-regional cooperation helps to promote the integration of resource elements and achieve a win–win situation between cities. The research results are intended to serve as an important guide and reference for the FDUA, the Urban Agglomeration on the West Side of the Straits as well as other small and middle urban agglomerations and other ecological civilisation demonstration zones in regulating the intensive use of resources, jointly protecting and controlling the ecological environment and developing cross-regional cooperation.
•The shortcomings of traditional CCDM are revealed.•An improved coupling coordination degree method based on game theory is proposed.•The validity of the improved CCDM is verified in the Yangtze ...River Economic Belt.•Coupling coordination between mineral resource exploitation, economy, and environment are measured.
A meaningful evaluation of the coordination of mineral resource exploitation, economy, and environment has practical significance for high-quality economic development. An improved coupling coordination degree model (CCDM) is established to evaluate the coupling coordination degree (D) between mineral resource exploitation, economy, and environment. The improved CCDM is based on game theory and objectively assigns contribution coefficients to subsystems, preventing subjective assignment of coefficients in traditional models. The performance of the improved CCDM is demonstrated in a case study of 11 provinces in the Yangtze River Economic Belt in 2009–2017. The results show the following: (1) The improved CCDM accurately reflects the conditions in the provinces. (2) The average D of 11 provinces shows an increasing trend, but the D has room for improvement. (3) Zhejiang, Sichuan, and Jiangsu are the top three performing provinces, and Shanghai is the bottom performer. (4) The regional distribution of D in the Yangtze River Economic Belt shows that downstream provinces have a higher D.
•The ecological health from 2005 to 2018 was maintained at relative low levels.•The ecological health will gradually be improved since 2019.•The deterioration in landscape patterns and aquatic ...environment quality due to human activity is the driving factor affecting regional ecological health.•Global Orchestration is the most desirable ecosystem management model.
Bay areas are special ecological transition zones where land and sea meet, and the ecological health of the region is an essential foundation for sustainable development. Therefore, it is crucial to establish an ecological health evaluation index system to assess the ecological health sustainability in bay areas for developing coastal zone management plans. This study proposes a cross-jurisdiction framework for assessing the ecological health in Xiamen Bay at multi-scales and multi-levels. The entropy weight and comprehensive index methods are then used to evaluate the ecological health in Xiamen Bay coupling ecological integrity and biodiversity with ecosystem services. Finally, a system dynamics model was established to analyze the sustainability of ecological health in Xiamen Bay. The results show that the overall ecological health level in Xiamen Bay continuously maintained <0.6 from 2005 to 2018, which is locating at critical and early warning status, and a shift from critical to good status starts in 2021; (2) under conditions of current development, the future population density, the total number of tourists arrived, artificial shoreline length, patch density, landscape diversity, habitat, and estuarine nutrient fluxes achieve the early warning status, which greatly constraining the sustainability of regional ecological health; (3) Global Orchestration is the most desirable ecosystem management model for the future. The ecological health in Xiamen Bay will achieve 0.7 and above in 2025 if following Global Orchestration pattern. This health value is locating at “good” status, and closes the gap to ecological sustainability level (ideal status with 0.8) in the region. This model is critical to form strategies and to ensure the ecological sustainability in the region.
At present, water pollution is still a serious problem in some parts of China. Clean water corridor technology (which provides water quality assurance and pollution load reduction from the Major ...Science and Technology Program for Water Pollution Control and Treatment) is a river pollution control and treatment measure. However, due to the differences of specific river conditions, it is not initially clear which technology can be used to obtain the best effect. Numerical simulation can address this issue. The results can be used as the basis for selecting clean water corridor technology. Combined with remote sensing (RS) and geographic information system (GIS) technology, the relationship between land use and non-point source pollution load was analyzed by using the HSPF (Hydrological Simulation Program-Fortran) model. According to the distribution of pollution load, the effect of the clear water corridor technology and its combination scenario on the reduction of non-point source pollution in the basin was simulated, and the best clear water corridor technology scheme for the control of non-point source pollution was identified. Research results show that from 2015 to 2018, the non-point source pollution load of total nitrogen in the Paihe River basin showed an overall increasing trend, while the total phosphorus showed a slightly increasing trend. Agricultural land and construction land accounted for 70% and 20%, respectively, of the non-point source pollution load, and the change in land use played an important role in the load of non-point source pollution. In terms of spatial distribution, the non-point source pollution of total nitrogen and total phosphorus was mainly concentrated in the downstream region and the central region. The non-point source pollution load reduction rates of total nitrogen and total phosphorus by the three types of clean water corridor technologies of vegetation buffer zones, permeable sidewalks and constructed wetlands, and their combinations were 15.29% and 15.03%, 11.93% and 11.48%, 8.96% and 8.67%, and 24.12% and 23.20%, respectively. It is necessary to comprehensively adopt clean water corridor technology for an optimal allocation and reasonable layout and to increase the pollution load reduction rate to further achieve ecological environment restoration goals.
Graphical abstract
Display omitted
•Anammox-HAP coupled process was run for nitrogen removal and phosphorus recovery.•The formation of HAP crystals in the anammox-HAP coupled process was verified.•The synergistic ...mechanism of anammox and HAP crystallization was clarified.•The inhibition thresholds of phosphate and free HAP were obtained.•A formula of calcium dosage at various phosphorus concentrations was provided.
Based on the requirements for advanced treatment and resource recovery of nitrogen and phosphorus pollutants in wastewater, the coupled anammox and hydroxyapatite crystallization (anammox-HAP) process was studied with an aim of achieving high efficiency and low energy consumption during simultaneous nitrogen and phosphorus removal. In the long-term experiments and batch tests, the effects of substrate conditions (nitrogen and phosphorus load, calcium concentration, etc.) on the nitrogen removal and phosphorus recovery efficiencies were investigated. The granular structure and crystal properties were analyzed together with microscopic characterization methods, and the formation mechanism of coupled anammox-HAP granules was verified. Based on these experiments, a theoretical model and technical method for realizing the coupled process were established, and a reference for practical engineering application was provided.
This paper identifies and examines social-economic and environmental issues recently emerged in China's coastal zone. Evaluation of management scheme and progress in perspectives of coordinated ...legislation, institutional arrangement, public participation, capacity building, and scientific research (mainly coastal planning and functional zoning) in China's coastal zone are made. The Chinese government has made a significant effort in developing legislation for the coastal zone. Jurisdictional and zoning boundaries, and allocating use rights for coastal and marine resources have been established. State Oceanic Administration is the leading agency responsible for China's ocean policymaking and overall management of ocean and coastal affairs. A demonstrated project for integrated coastal management in Xiamen has been implemented, and is characterized as “decentralization” approach in decision-making process. In view of the above, comprehensive coastal management in China is a big challenge, facing with many difficulties. Finally, recommendations are raised for tackling these issues for China's coastal zone management.
In recent times, deep neural networks achieved outstanding predictive performance on various classification and pattern recognition tasks. However, many real-world prediction problems have ordinal ...response variables, and this ordering information is ignored by conventional classification losses such as the multi-category cross-entropy. Ordinal regression methods for deep neural networks address this. One such method is the CORAL method, which is based on an earlier binary label extension framework and achieves rank consistency among its output layer tasks by imposing a weight-sharing constraint. However, while earlier experiments showed that CORAL’s rank consistency is beneficial for performance, it is limited by a weight-sharing constraint in a neural network’s fully connected output layer, which may restrict the expressiveness and capacity of a network trained using CORAL. We propose a new method for rank-consistent ordinal regression without this limitation. Our rank-consistent ordinal regression framework (CORN) achieves rank consistency by a novel training scheme. This training scheme uses conditional training sets to obtain the unconditional rank probabilities through applying the chain rule for conditional probability distributions. Experiments on various datasets demonstrate the efficacy of the proposed method to utilize the ordinal target information, and the absence of the weight-sharing restriction improves the performance substantially compared to the CORAL reference approach. Additionally, the suggested CORN method is not tied to any specific architecture and can be utilized with any deep neural network classifier to train it for ordinal regression tasks.
Display omitted
•MPs altered nitrogen (N) turnover in mangrove sediments.•Stochiometric and enzymatic ratios showed MPs intensified N limitation.•MPs shifted the microbial communities from r- to ...K-strategists.•MPs promoted DNRA rates but inhibited N2O production for efficient N utilization.
Mangrove wetlands are hotspots of the global nitrogen (N) cycle and important sinks of microplastics (MPs) due to their ecotone location between terrestrial and marine ecosystems. However, the effects of MPs on N cycle processes in mangrove ecosystems are still poorly understood. Thus, the present study assessed the impacts by adding MPs to mangrove sediments in a microcosm incubation experiment. The results showed that MPs increased dissolved organic carbon and nitrate but reduced ammonium contents in the sediments. MPs increased C:N stoichiometric and N:C-acquiring enzymatic ratios, indicating an intensified N limitation in mangrove sediments following exposure of MPs. MPs decreased microbial community diversity and shifted sediment microbial communities from r- to K-strategists, consistent with the intensified N limitation. In response, dissimilatory nitrate reduction to ammonium (DNRA) rates increased while nitrous oxide (N2O) production reduced suggesting more efficient N utilization in MPs treatments. The MPs with heteroatoms such as PLA- and PVC-MPs, increased DNRA rates by 67.5–78.7%, exhibiting a stronger impact than PE-MPs. The variation partitioning analysis revealed that the variances of DNRA rates and N2O production could be attributed to synergistic effects of physicochemical properties, nutrient limitation, and microbial community in mangrove sediments. Overall, this study provides pertinent insights into the impacts of MPs as a new carbon source on nutrient limitation and N turnover in mangrove ecosystems.
To achieve efficient and stable nitrogen removal and low N2O emission in the single-stage partial nitrification (PN)-anaerobic ammonium oxidation (anammox) process, a sequence batch reactor (SBR) was ...operated for 223 days, the optimal operation strategies were investigated. Aeration rate control was applied to achieve the synergy between anammox and partial nitrification. The variation of specific anammox activity (SAA), specific ammonia oxidizing bacteria activity (SAOA), and specific nitrite oxidizing bacteria activity (SNOA) revealed that the anammox process was a rate-limiting step under low-strength ammonium loading condition. With the long-term acclimation, the anammox process showed more tolerance to substrate variation, in contrast, the inhibitory threshold concentration of partial nitrification to ammonium was decreased. The evolution of specific activities and substrate tolerance abilities of the functional microbes verified the changes in the nitrogen removal performance and proved that the aeration control strategy was efficient for operating a low nitrogen loading PN-anammox reactor. The nitrous oxide (N2O) isotopic composition analysis revealed that 73% of N2O was produced via the nitrifier denitrification pathway. N2O production could be mitigated by increasing the SAA in the PN-anammox process. The reveal of the synergy effect between functional microbes and the N2O pathway provide a guidance for operating a PN-anammox system for treating low nitrogen loading wastewater.
Display omitted
•Aeration control is efficient for operating PN-anammox system with low NLR.•The anammox process is a rate-limiting step under low NLR.•The substrate tolerance ability of AnAOB was significantly improved.•Nitrifier denitrification is the dominant pathway of N2O production.
Tanshinones, one group of bioactive diterpenes, were widely used in the treatment of cardiovascular diseases. WRKYs play important roles in plant metabolism, but their regulation mechanism in
remains ...elusive. In this study, one
transcription factor
was isolated and functionally characterized from
. Multiple sequence alignment and phylogenetic tree analysis showed SmWRKY1 shared high homology with other plant WRKYs such as CrWRKY1.
was found predominantly expressed in leaves and stems, and was responsive to salicylic acid (SA), methyl jasmonate (MeJA), and nitric oxide (NO) treatment. Subcellular localization analysis found that SmWRKY1 was localized in the nucleus. Over-expression of
significantly elevated the transcripts of genes coding for enzymes in the MEP pathway especially 1-deoxy-D-xylulose-5-phosphate synthase (
) and 1-deoxy-D-xylulose-5-phosphate reductoisomerase (
), resulted in over fivefold increase in tanshinones production in transgenic lines (up to 13.7 mg/g DW) compared with the control lines. A dual-luciferase (Dual-LUC) assay showed that SmWRKY1 can positively regulate
expression by binding to its promoter. Our work revealed that SmWRKY1 participated in the regulation of tanshinones biosynthesis and acted as a positive regulator through activating
in the MEP pathway, thus provided a new insight to further explore the regulation mechanism of tanshinones biosynthesis.
PDF
